Arteriovenous fistula patency in the 3 years following vonapanitase and placebo treatment.

OBJECTIVE: This study explored the long-term outcomes of arteriovenous fistulas treated with vonapanitase (recombinant human elastase) at the time of surgical creation. METHODS: This was a randomized, double-blind, placebo-controlled trial of 151 patients undergoing radiocephalic or brachiocephalic arteriovenous fistula creation who were randomized equally to placebo, vonapanitase 10 µg, or vonapanitase 30 µg. The results after 1 year of follow-up were previously reported. The current analysis occurred when the last patient treated was observed for 3 years. For the current analysis, the primary end point was primary patency; the secondary end points included secondary patency, use of the fistula for hemodialysis, and rate of procedures to restore or to maintain patency. RESULTS: There was no significant difference in the risk of primary patency loss with vonapanitase 10 µg or 30 µg vs placebo. When seven initial patency loss events related to cephalic arch and central vein balloon angioplasty were excluded, the risk of patency loss was reduced with vonapanitase overall (hazard ratio [HR], 0.63; P = .049) and 30 µg (HR, 0.51; P = .03). In patients with radiocephalic fistulas (n = 67), the risks of primary and secondary patency loss were reduced with 30 µg (HR, 0.37 [P = .02] and 0.24 [P = .046], respectively). The rate of procedures to restore or to maintain fistula patency was reduced with 30 µg vs placebo (0.23 vs 0.72 procedure days/patient/year; P = .03) and also reduced in patients with radiocephalic fistulas with 30 µg vs placebo (0.17 vs 0.85 procedure days/patient/year; P = .048). CONCLUSIONS: In this study, vonapanitase did not significantly improve primary patency in the primary analysis but did significantly improve primary patency in an analysis that excluded patency loss due to cephalic arch and central vein balloon angioplasty. In patients with radiocephalic fistulas, 30 µg significantly improved primary and secondary patency. Vonapanitase 30 µg decreased the rate of procedures to restore or to maintain patency in the analysis that included all patients and in the subset with radiocephalic fistulas.

Outcomes after combined liver-kidney transplant vs. kidney transplant followed by liver transplant.

INTRODUCTION: The decision for isolated kidney transplant (KT) vs. combined liver-kidney transplant (CLKT) in patients with end-stage renal disease (ESRD) with compensated cirrhosis remains controversial. We sought to determine outcomes of patients requiring listing for a liver transplant (LT) following either a cadaveric or living donor KT and compare these outcomes to similar patients receiving a CLKT. METHODS: Our dataset included the United Network for Organ Sharing (UNOS)/Standard Transplant and Analysis and Research (STAR) kidney files from 1987 to 2012 after being joined with the liver files from 2002 to 2012. Outcomes of patients who received a CLKT with an international normalized ratio (INR) ≤1 and total bilirubin ≤1 were compared to patients who received a primary KT and subsequently required listing for LT between zero and five yr or after five yr. RESULTS: For the three groups, 244 patients had a CLKT, 216 were wait-listed for LT between zero and five yr after KT (0-5 WL), and 320 were wait-listed five yr after KT (+5 WL). From the time of KT, the 0-5 WL group had significantly worse survival than the CLKT group and the +5 WL group. The +5 WL had the best survival of all groups. For the 0-5 WL group, 45% underwent LT and 40% died while waiting compared to the +5 WL group with 53% having LT and 26% died while waiting. At the time of LT, the 0-5 WL group had a higher model for end-stage liver disease (MELD) score, higher incidence of being in the ICU at the time of transplant, and higher incidence of requiring life support. From the time of LT, the CLKT trended toward better survival (p = 0.0549) than both the 0-5 WL and +5 WL groups, which had equivalent survival. CONCLUSION: The 0-5 WL group is a higher risk group with poorer survival due to a higher incidence of dying on the waitlist. Better identification of patients with a high risk for hepatic decompensation following KT and agreement for regional exception for LT in the event of decompensation may improve utilization of organs and better survival for those patients.

Human type I pancreatic elastase treatment of arteriovenous fistulas in patients with chronic kidney disease.

OBJECTIVE: This study explored the safety and efficacy of recombinant type I pancreatic elastase (PRT-201) topically applied once to the external surface of an arteriovenous fistula. METHODS: This was a randomized, double-blind, placebo-controlled trial. Adults with kidney disease undergoing creation of a radiocephalic fistula (RCF) or brachiocephalic fistula were randomized to treatment with placebo (n = 51), PRT-201 at 10 µg (n = 51), or PRT-201 at 30 µg (n = 49). The primary efficacy measure was unassisted primary patency (PP) over 1 year. Secondary efficacy measures were secondary patency (SP), unassisted maturation by ultrasound interrogation, use for hemodialysis, and hemodynamically significant lumen stenosis. RESULTS: Median PP was 224 days for placebo and >365 days for the PRT-201 groups. At 1 year, 45%, 54%, and 53% of placebo, 10-µg, and 30-µg patients retained PP. The risk of PP loss was nonsignificantly reduced for 10 µg (hazard ratio [HR], 0.69; P = .19) and 30 µg (HR, 0.67; P = .17) vs placebo. In the subset (44% of patients) with a RCF, the median PP was 125 days for placebo and >365 days for the PRT-201 groups. At 1 year, 31%, 50%, and 63% of placebo, 10-µg, and 30-µg RCFs retained PP. The risk of RCF PP loss was nonsignificantly reduced by 10 µg (HR, 0.59; P = .18) and significantly reduced by 30 µg (HR, 0.37; P = .02) vs placebo. At 1 year, 77%, 81%, and 83% of placebo, 10-µg, and 30-µg patients retained SP. The risk of SP loss was nonsignificantly reduced for 10 µg (HR, 0.79; P = .61) and 30 µg (HR, 0.76; P = .55) vs placebo. In the subset with RCFs, 65%, 82%, and 90% of placebo, 10-µg, and 30-µg patients retained SP at 1 year. The risk of RCF SP loss was nonsignificantly reduced for 10 µg (HR, 0.45; P = .19) and 30 µg (HR, 0.27; P = .08) vs placebo. At month 3, 67%, 87% (P = .03), and 92% (P < .01) of the placebo, 10-µg, and 30-µg group fistulas had unassisted maturation by ultrasound interrogation. At month 3 in the subset with an RCF, 47%, 74% (P = .17), and 93% (P < .01) of placebo, 10-µg, and 30-µg group fistulas had unassisted maturation by ultrasound interrogation. Adverse event reports were not meaningfully different between groups. CONCLUSIONS: PRT-201 appeared safe. The primary efficacy end point was not met. However, both PRT-201 doses were associated with improved unassisted maturation. The 30-µg dose was associated with increased PP in the subset with RCF.

Balloon-assisted over-the-wire technique for placement of the venous outflow component of the Hemodialysis Reliable Outflow (HeRO) device.

A modified technique for placement of the venous outflow component (VOC) of the Hemodialysis Reliable Outflow (HeRO) device (Hemosphere Inc, Minneapolis, Minn) is described. The purpose of the technique is to improve the system's trackability and facilitate device insertion in patients with central venous occlusion. Device preparation requires placement of a 6-mm × 4-cm angioplasty balloon within the leading end of the VOC. The leading 2 cm of the balloon are placed just distal to the radiopaque marker of the VOC. The balloon is inflated to profile and locked in this position within the leading end of the VOC. The VOC and balloon combination is advanced over the wire through the 20F peel-away sheath provided by the manufacturer. The described technique was used to successfully implant the HeRO device in 12 patients with central venous occlusion. This technique is recommended for placement of the VOC of the HeRO device in patients with central venous occlusions.

Graft repair of arteriovenous fistula aneurysms is associated with decreased long-term patency.

INTRODUCTION: Arteriovenous fistula (AVF) aneurysms are a chronic complication which can be disfiguring, painful, and can rupture. Here, we compare the outcomes between three different methods of AVF aneurysm repair. METHODS: One-way ANOVA, Chi-square, and Fisher Exact analyses were used to compare demographics. Multivariate logistic regression compared outcomes. Kaplan-Meier estimate illustrated long-term fistula patency. RESULTS: There were no differences between demographics in the aneurysmorrhaphy, end-to-end anastomosis, and synthetic graft groups. The odds of patients who received graft repair losing primary patency within one year compared to the aneurysmorrhaphy group was 3.5 (p = 0.025). Graft repair patients were 6.7 times more likely to develop an infection compared to aneurysmorrhaphy (p = 0.014). Synthetic grafts also exhibited accelerated rates of complete access loss compared to autogenous methods (p = 0.034). CONCLUSIONS: Graft repair of AVF aneurysms results in higher rates of infection and decreased primary and ultimate patency compared to autogenous repair techniques. Therefore, synthetic grafts should be avoided whenever possible.

End-to-end anastomosis as a superior repair type to prevent recurrence of arteriovenous fistula aneurysms and improve patency outcomes.

BACKGROUND: Arteriovenous fistulae (AVF) complicated by aneurysms are repaired through several mechanisms. Little is known about risk factors for aneurysm recurrence or the efficacy of subsequent repair of recurring aneurysms. METHODS: About 291 patients underwent AVF aneurysm repair between 2009 and 2019 at a large urban medical center. Patients who underwent staged repair, had a primary graft with pseudoaneurysm, were status-post kidney transplant, or using other dialysis access at the time of repair were excluded. One hundred sixty-two patients were included in the study, of which 52 developed a secondary aneurysm. Chi-square and t-test analyses were used to compare demographics. Multivariate logistic regression was used to examine independent risk factors for aneurysm recurrence. Of the 52 patients with recurrent aneurysms, 41 were repaired again. Patency was examined for each group 1 year postoperatively. RESULTS: Patients without secondary aneurysms were more likely to have a Charlson Comorbidity Index score ⩾5 (p = 0.045). Males were 2.8 times more likely to develop a secondary aneurysm compared to females (p = 0.023). Patients who underwent elective compared to emergent or urgent surgery for primary aneurysms were significantly less likely to recur (OR = 0.222; p = 0.016). Primary aneurysms repaired by end-to-end anastomosis, compared to aneurysmorrhaphy or graft, were significantly less likely to recur (OR = 0.239; p = 0.041). Among patients with secondary aneurysms, those repaired via end-to-end anastomosis had a significantly higher primary patency rate 1 year postoperatively (p = 0.024). Secondary aneurysm repairs exhibited 1-year primary and secondary patency rates of 51.2% and 82.9%, respectively. CONCLUSIONS: End-to-end anastomosis reduces risk of recurrence and demonstrates superior patency rates when repairing recurrent aneurysms. It remains unclear why some patients are prone to aneurysm recurrence, however continued attempts to repair existing vascular access are proven to be successful.

A long-term comparison of tacrolimus (FK506) and cyclosporine in kidney transplantation: evidence for improved allograft survival at five years.

BACKGROUND: The 1-year results of the Phase III U.S. Multicenter Trial comparing tacrolimus (FK506)- and cyclosporine (CsA)-based immunosuppressive therapy in kidney transplantation revealed a significant reduction in the incidence and severity of acute rejection episodes among patients maintained on tacrolimus. The present report at 5 years of follow-up focuses on the long-term impact of tacrolimus treatment on kidney allograft outcome. METHODS: The study protocol permitted crossover of patients to the alternate treatment arm under stringent conditions. The effect of crossover on graft survival was analyzed. Cardiovascular risk factors and serious adverse events were also monitored over 5 years. RESULTS: Intent-to-treat analysis revealed equivalent patient and graft survival between treatment arms at 5 years of follow-up (79.1% vs. 81.4%; P=0.472 and 64.3% vs. 61.6%; P=0.558 among tacrolimus and CsA-treated patients, respectively). However, the rate of crossover was significantly higher among patients randomized to receive CsA-based therapy (27.5% vs. 9.3%; P<0.001). The incidence of treatment failure (43.8% vs. 56.3%; P=0.008) was significantly lower among tacrolimus-treated patients. Graft survival was significantly improved in the tacrolimus treatment arm when crossover due to rejection was counted as graft failure (63.8% vs. 53.8%; P=0.014). Tacrolimus therapy was also associated with a significantly reduced requirement for medications to control hypertension and hyperlipidemia. There was a substantial rate of reversal of tacrolimus-associated insulin dependence. CONCLUSION: Tacrolimus-based therapy resulted in significantly reduced risk of graft failure, without an increase in the incidence of adverse events associated with long-term immunosuppression.